Economic Considerations of Climate Change and Health

Economics govern the relationship between what could be done and what is actually done. A fundamental rule of public health posits that it is medically and economically desirable to prevent rather than to treat an illness. Heat leads to more deaths than any weather-related cause. In the July 2006 California heat wave there were over 16,000 excess emergency room visits and 1,100 hospitalizations. In Washington, there were 3.1 heat-related workman’s compensation claims per 100,000 full time employees. In India the economic burden of dengue is over one billion dollars per year. Puerto Rican data suggest it is the most important and costliest vector-borne disease. Property loss and burdens associated with the production of climate change refugees add to the cost of rising sea level. It’s no surprise that careful studies in the US show that those with the highest social vulnerability will be the most seriously affected. Agriculture will suffer: the 2012 megadrought cost around $30 billion. Economists estimate that heat-related increases in crime will cost each US citizens between $20 and $30 per year by the end of the century.

Air Pollution, Air Quality, and Climate Change

The effects of climate change on air quality are difficult to model due to the large number of unpredictable variables. Hotter temperatures favor ozone production. Higher atmospheric water content may blunt this effect in some regions. Higher levels of natural volatile organic compounds (VOCs), such as terpenes from plants, are likely to act synergistically with anthropogenic VOCs to favor ozone production. Droughts increase wildfire risks that produce particulate pollution and carbon monoxide, a VOC involved in ozone production. Some models predict increased ozone concentrations in many urban settings. Future revisions of National Ambient Air Quality Standards, a process driven by politics and science, should consider these effects.

Sea Level Rise and Environmental Refugees

Sea levels are rising as a result of thermal expansion of oceanic water and the melting of the ice that covers Greenland and in glaciers all over the world. This added to the effect of storm surges that are likely to be higher as storm intensity increases poses threats to coastal cities around the world. Lessons learned from Superstorm Sandy and Typhoon Bhola, which killed around 500,000, are two of the most important disasters of the past century. Business-as-usual emissions will worsen these effects.

Climate Change, Agriculture, and Famine

Hotter weather and higher atmospheric CO2 levels will have profound effects on plants. Crops such as corn and soybeans, have critical temperature thresholds above which yields fall precipitously. High CO2 levels will foster the growth of many weeds over crops, threatening yields. Stimulated growth and release of ragweed allergens will threaten hay fever sufferers and asthmatics. The nutrient content of many crops falls in a high CO2 environment. As crop yields fall, prices rise, and undernutrition increases, particularly among children who fail to develop normally who, as a result, may not achieve normal intelligence. In many nations, particularly in Sub-Saharan Africa, childhood undernutrition already approaches 50%. Feeding the increasing population of the world may become problematic.

Infectious Diseases

A warmer climate will exert multiple and diverse effects on ecological systems. Climate change will affect disease vectors, especially mosquitoes, and disease-causing organisms, such as the protozoa that cause malaria, bacteria, and viruses. Malaria will spread to higher latitudes and altitudes. Without mitigation and adaptation to climate change half of the world’s population is likely to be at risk for contracting dengue before 2100. Lyme disease is already spreading. Hantavirus infections, which may have a 40% mortality, are likely to hospitalize as many as 200,000 individuals annually according the most recent IPCC report. Water-borne illnesses, particularly cholera, are likely to follow in the wake of tropical storms, as was the case in post-earthquake Haiti where a severe outbreak followed flooding due to Hurricane Tomas. Understanding disease ecology will become increasingly important.

Protecting Health

In public health terms, primary climate change prevention means reducing emissions of greenhouse gases and secondary prevention refers to adaptation to climate change. Renewable energy sources depending on the sun, wind, and water power must replace the use of fossil fuels. The IPCC has identified heat, undernutrition, and food and water-borne illnesses as the health domains at greatest risk on a warming world. These are also the domains where the greatest opportunities for the effects of mitigation and adaptation exist. Planning for the future and allocating appropriate resources are critical for success. Compare Florida, where the governor banned the term climate change and plans for the future are often aspirational, to the Netherlands where massive public works projects protect the Dutch from the sea. Education, research, and political will must be guided by evidence-based decision-making if future generations are to enjoy good health on a hospitable planet.

Violence, Conflict, and Societal Disruption

Diverse studies of traffic, baseball, crime-temperature relationships, and others, support the hypothesis that heat breeds violence at a time when, in the US, violent crime is on the wane. Droughts and deluges lead to environmental insecurity by many mechanisms as reflected in an examination of social conflicts in Africa. Rising food prices also foster riots. Climate change is an important factor that has led to societal collapse. Other weather and climate changes, such as those associated with El Niño, are also linked to societal disruption. These relationships have contributed to the current violence in the Middle East.

Heat and Severe Weather

A hotter climate means there will be more heat waves and heat-related illnesses, such as heat exhaustion and heat stroke, the leading causes of weather-related death in the US. Without mitigation, annual world-wide heat-related deaths may exceed 225,000 by 2050. Heat will spawn more extreme weather events such as severe thunderstorms, and tornadoes. Although the number of hurricanes may not increase, the moisture-laden air and warmer oceans will make those that do form more intense and deadly.

The Scientific Evidence for Climate Change

The instrumental record shows steadily rising global surface temperatures as the atmospheric concentration of carbon dioxide and other greenhouse gases increased during the industrial age. Numerous complementary scientific techniques have shown clearly that these increases are due to human activity, notably burning fossil fuels. The instrumental record is complemented by proxy measurements that reliably document the earth’s temperature and the atmospheric concentration of carbon dioxide for hundreds of thousands, and in some cases, millions of years. Present conditions are unprecedented in those time frames. Without drastic reductions in the emission of carbon dioxide the worst is yet to come.

Introduction

Health, a state of complete physical, mental, social well-being and freedom from disease, depends on the ecosystems in which we live. For example, climate change results in increased temperatures that lead to heat illnesses, drought, crop failure, undernutrition, the spread of disease etc. To focus on the maintenance of ecosystems and health the UN published Sustainable Development Goals, while health professionals have enumerated causes of death and health risk factors susceptible to a changing climate. To mitigate climate change, and hence risk factors for disease, we must adapt to climate change. This requires political will, stakeholder involvement, education, research, and adequate funds.